The test by Songsheng Jiang has revealed something truly significant about the nature of how the E-Cat produces excess heat, in my opinion.

The reactor is setup in a unique manner. A thermocouple is placed on the inside of a rectangular nickel container holding the fuel. This thermocouple was damaged so it can be for most purposes ignored. A second thermocouple was placed on the outside of the nickel container. This whole setup was then placed inside of a cylindrical stainless steel chamber. An additional thermocouple was placed between the outside surface of the stainless steel chamber and a resistor. Next, all of these components were placed in a ceramic housing. (See Jiang’s diagram below)

Between the thermocouple on the outside of the innermost chamber and the outside of the stainless steel chamber there is a significant thermal barrier. Songsheng mentions in an answer in the Q and A recently posted that heat was very slow to transfer from the resistors to the interior reactor chamber. This means that an increase in temperature of the resistors would not result in an instant heat up of the outer surface of the nickel chamber.

On several occasions, when the voltage to the resistors is increased, there is a sudden, almost instantaneous burst of heat generated in the core. The thermocouple sitting on the outside of the nickel chamber soars to a temperature beyond what can be registered – around 1370C. The temperature of the resistors, however, is slow to increase. The temperature of the thermocouple near the resistors lags the thermocouple on the outside of the nickel chamber. (See below)

This cleaner version of this slide provided by S. Jiang to LENR-CANR.org (see here: http://lenr-canr.org/Collections/Jiang%20DATA%202015-May-04%20to%20May-07.pdf)

The only explanation that makes sense, in my opinion, is that there is a stimulating factor propagating from the resistors to the fuel at a very high speed. This must be the magnetic field produced by the resistors.

A significant portion of the stimulation in the Ni-LiAlH4 E-Cat is magnetic. This would match what Rossi and Cook in their recently published paper “On the Nuclear Mechanisms Underlying the Heat Production by the E-Cat”:

” . . . As important as the solid-state environment and the surrounding electromagnetic field is for inducing nuclear effects, the nuclear reactions themselves appear to occur only in a few specific isotopes and involve only a few specific quantal transitions” (p. 10, emphasis added)

When using DC, the only time the magnetic field can change is when the current increases or decreases. However, with AC, the magnetic field could be far more avaialble to impact the fuel at any power level. This is because due to the nature of AC the field is changing constantly. Only the frequency and harmonics would need to be adjusted to stimulate excess heat producing when using AC. Hence, AC may allow the fuel to be stimulated at the same or lower power level without having to increase the total power. Using DC power may be a wasteful way of providing magnetic stimulation, because the power must be increased. It is possible that with a low power a suitable magnetic field could be produced using AC current.